I read (second comment to this question, which doesn'r offer no solace ar all)
If there are two people who are exactly the same then either they are the same person (via the law of identity) or they are different people.
This sounds like non-sense to me. How can two co-existing people who are exactly the same be the same person? How can a law of identity prevent this? Doesn't the fact that two persons who have a separate existence (in space or in time or in spacetime) already makes them two non-identical persons? What is this "law of identity"?